1. Field of the Invention
The present invention relates to a method and a device for removing a defective product from a path through which products are continually fed, the products having a constant length and being, for example, tubes which are used for the cores of a radiator or heater of an automobile.
2. Description of the Related Art
Defects often occur in the production of tubes, for example, a faulty welding joint in belt material from which the tube is produced, a large size error in the sectional shape of the tube, and inferior plating of the tube. In a conventional tube manufacturing process, defective tubes are removed from the production line by a process in which, first an operator marks the defective portions, and after the products are cut to a constant length, another operator then removes the marked products or other defective products in which the defects are easily distinguishable by the naked eye.
In the above system, an operator must be specially designated to manually remove the defective products. However, defective products may be passed by the operator because the defects are not easily distinguishable or the marks cannot be seen. Also, in some cases, the entire system may have to be stopped for the removal of defective products, which is not preferable from the viewpoint of productivity.